Embeddable module for high output led

ABSTRACT

In one aspect, a light module is disclosed, which includes a housing providing a hollow chamber extending from a proximal end to a distal end, and a lens positioned in the hollow chamber, where the lens has a lens body comprising an input surface for receiving light from a light source and an output surface through which light exits the lens body, said lens further comprising a collar at least partially encircling said lens body. The light module further includes at least one shoulder on which the lens collar can be seated for positioning the lens within the housing. A light source, e.g., an LED, is coupled to the hollow chamber, e.g., at its proximal end, for providing light to the lens.

RELATED APPLICATION

The present application claims priority to a provisional patentapplication entitled “Embeddable module for light output LED” having anapplication No. 62/247,454 filed on Oct. 28, 2015, and a provisionalpatent application entitled “Elliptical optical lens for high outputLED” having an application No. 62/247,451 filed on Oct. 28, 2015, and aprovisional patent application entitled “Handheld mobile light source”having an application No. 62/247,456 filed on Oct. 28, 2015, each ofwhich is herein incorporated by reference in its entirety.

The present application is also related to utility patent applicationsentitled “Elliptical optical lens for high output LED” and “Handheldmobile light source” that are being filed concurrently herewith and arehereby incorporated by reference in their entirety.

BACKGROUND

The present invention relates generally to a light module that can beembedded in a variety of devices, such as endoscopes, to provide lightfor illuminating a field of view. In many embodiments, the light modulecan provide high intensity, low heat light.

SUMMARY

In one aspect, a light module is disclosed, which includes a housing(e.g., a handheld housing) providing a hollow chamber extending from aproximal end to a distal end, and a lens positioned in the hollowchamber, where the lens has a lens body comprising an input surface forreceiving light from a light source and an output surface through whichlight exits the lens. The lens further includes a collar that at leastpartially encircles the lens body. The light module further includes atleast one shoulder disposed in the hollow chamber and in contact withthe lens collar for providing mechanical support to the lens. By of wayof example, the shoulder can be provided by at least one sleeve placedin contact with the lens collar to provide mechanical support to thelens. A light source is coupled to the hollow chamber at the proximalend thereof (e.g., positioned within the hollow chamber) for providinglight to the input surface of the lens. In some embodiments, the lightmodule can include an optical window disposed in the hollow chamber andoptically coupled to the output surface of the lens such that the lightexiting the lens passes through the optical window before exiting thelight module. In many embodiments, the lens can be removably andreplaceably positioned in the hollow chamber.

A variety of light sources can be employed. In some embodiments, thelight source can include one or more light emitting diodes (LEDs). Avariety of LEDs emitting radiation at different wavelengths, such aswavelengths in the ultraviolet, infrared, far-infrared, and visibleportions of the electromagnetic spectrum can be employed.

The optical window can be formed of a variety of different materials.Some examples of suitable materials include, without limitation,sapphire, quartz, and glass. In some embodiments, the window can alsofunction as a filter for blocking certain wavelengths of light whileallowing other wavelengths to pass therethrough. For example, theoptical window can function as a high pass, a low pass or a bandpassfilter. By way of example, the optical window can block ultraviolet andinfrared wavelengths while allowing visible wavelengths to passtherethrough.

In some embodiments, the light module further includes a retainingwindow that is removably and replaceably coupled to the light module'shousing, e.g., at its distal end. By way of example, in some suchembodiments, the retaining window can include a plurality of threadsthat can removably and replaceably engage with a plurality of threads(e.g., internal threads) provided at the distal end of the lightmodule's housing.

In some embodiments, the retaining window can include an internalchannel extending from a proximal opening to a distal opening forcoupling via the distal opening to a light guide, e.g., via an adapterto which the light guide is connected.

In some embodiments, a gasket can be disposed between the retainingwindow and the optical window to provide a seal therebetween. In somesuch embodiments, the retaining window presses against the gasket toprovide the seal and further provide mechanical support to the opticalwindow.

The light source (e.g., an LED) can be mounted on a printed circuit (PC)board disposed within the module's housing, e.g., at its proximal end.The board can include a plurality of electrical leads for coupling thelight module to a source of power for supplying power to the lightsource. Further, a plate can be connected to the proximal end of themodule's housing to facilitate securely holding the above componentswithin the housing and in some cases to facilitate sealing the interiorof the housing from the external environment. The plate can include aplurality of openings through which the electrical leads can protrudefor connecting to a source of power.

In some embodiments, the lens includes a lens body extending from aproximal section having said input surface to a distal section havingsaid output surface. The proximal section further comprises asubstantially elliptical peripheral surface receiving at least a portionof the light entering the lens body via said input surface and directingat least some of the received light via total internal reflection to thedistal section such that at least a portion of the light directed to thedistal section exits the lens body through said output surface. Theperipheral elliptical surface can be characterized by a proximal focalpoint and a distal focal point. In some embodiments, the distal focalpoint is positioned external to the lens, e.g., a distance above theoutput surface of the lens. For example, the distal focal point may bepositioned outside the lens body at a distance above the lens's outputsurface so as to be within a proximal portion of the light guide uponcoupling of the light guide to the light module. In other embodiments,the distal focal point may be positioned in the distal section of thelens body. In some embodiments, the distal focal point may be positionedat the output surface of the lens. Further, in some embodiments, theproximal focal point of the elliptical surface can be positioned, e.g.,at the light source or in close proximity thereto.

In some embodiments, the lens collar is disposed at the boundary betweenthe proximal and distal sections of the lens body.

In some embodiments, the lens can have an input surface having a centralconvex portion and a peripheral portion surrounding the central convexportion. In some embodiments, the peripheral portion of the inputsurface is shaped such that at least a portion of the light entering thelens body via the peripheral portion propagates to the peripheralelliptical surface to be reflected thereby. In some embodiments, theperipheral portion of the input surface is shaped such that at leastabout 80%, or at least about 90%, or at least about 95% (and preferably100%) of the light entering the lens body via that portion propagates tothe peripheral surface of the lens body to be reflected thereby. In someembodiments, the peripheral portion of the input surface includes aproximal concave segment and a distal convex segment.

In some embodiments, the convex portion of the input surface and/or theelliptical peripheral surface can exhibit a positive optical power in arange of about 50 to about 300 D. In some embodiments, the convexportion of the input surface is configured such that the light enteringthe lens body via that portion propagates to the lens' output surfacewithout striking the elliptical peripheral surface.

In some embodiments, the input surface forms a cavity configured toreceive at least partially the light source. In some embodiments, theproximal focal point of the elliptical peripheral surface is positionedin the cavity.

In some embodiments, the input surface of the lens is configured tocapture at least about 80%, or at least about 90%, or at least about 95%(and preferably 100%) of the light emitted by the light source.

In some embodiments, the lens body is rotationally symmetric about anoptical axis and its output surface is substantially flat and orthogonalto that axis.

Various components of the light module can be formed of a variety ofdifferent materials. For example, the lens can be formed of any suitablepolymeric material, such as polycarbonate, polymethylmethacrylate(PMMA). In some cases in which the LED emits radiation in the infraredregion of the electromagnetic spectrum, the lens may be formed of highdensity polyethylene (HDPE). In some embodiments, the module's housingand/or the sleeves can be formed of a metal or a plastic.

In a related aspect, a light module is disclosed, which includes ahousing providing a hollow chamber extending from a proximal end to adistal end, and a lens positioned in the hollow chamber, where the lenshas a lens body comprising an input surface for receiving light from alight source, an output surface through which light exits the lens bodyand a peripheral elliptical surface that directs light incident thereonvia total internal reflection to the output surface, said lens furthercomprising a collar at least partially encircling the lens body. Thelight module further includes at least one shoulder on which the lenscollar can be seated for positioning the lens within the housing. Alight source, e.g., an LED, is coupled to the hollow chamber, e.g., atits proximal end, for providing light to the lens. In some embodiments,an optical window is disposed in the hollow chamber and is opticallycoupled to the output surface of the lens such that the light exitingthe lens passes through the optical window before exiting the lightmodule. In some embodiments, the shoulder can be formed as part of thehousing. In other embodiments, the shoulder can be provided by a sleevedisposed in the module's housing.

In a related aspect, a device for providing illumination to a field ofview is disclosed, which includes a housing, a removable and replaceablelight module coupled to the housing, and one or more light guide(s)mechanically coupled to the housing and optically coupled to the lightmodule to receive light therefrom. In some embodiments, the housingincludes an enclosure for receiving the light module. In some suchembodiments, the light guide(s) are disposed within the housing and inoptical coupling with the light module to receive light therefrom. Thelight guide(s) can extend to an opening within the housing through whichthe light exiting the light guide(s) can exit the device to illuminate afield of view. By way of example, the device can be an endoscope, asurgical headlight, a video camera, a retractor, a speculum, and otherdevices requiring high intensity, high quality light.

By way of example, such a device can be an endoscope. In some suchembodiments, the endoscope can be a single-use endoscope.

In a related aspect, a light module is disclosed, which includes ahousing providing a hollow chamber extending from a proximal end to adistal end, a lens positioned in said hollow chamber, said lens having alens body comprising an input surface for receiving light from a lightsource and an output surface through which light exits the lens body,said lens further comprising a collar at least partially encircling saidlens body. The light module further includes at least one shoulder onwhich said collar is seated. A light source is coupled to the hollowchamber at the distal end for providing light to the input surface ofthe lens.

In some embodiments, an optical window (formed, e.g., of sapphire orquartz) is disposed in the hollow chamber and is optically coupled tothe output surface of the lens such that the light exiting the lenspasses through the window before exiting the light module.

In some embodiments, the light module includes at least one sleevedisposed in the hollow chamber, which provides the shoulder for holdingthe lens. In some embodiments, the shoulder is formed as protrusionextending into the housing from the inner wall of the housing.

In some embodiments, the lens includes a peripheral surface forreceiving at least a portion of the light entering the lens body viasaid input surface and for directing said received light via totalinternal reflection to the output surface. In some embodiments, theperipheral surface has a truncated elliptical shape characterized by aninput focus and an output focus. In some such embodiments, the inputfocus is positioned on or in proximity of the light source and theoutput focus is positioned external to said lens at a distance abovesaid output surface of the lens. In other embodiments, the output focusis positioned inside the lens, e.g., below the output surface or at theoutput surface of the lens.

In some embodiments, the light module can include a retaining windowremovably and replaceably coupled to the distal end of the housing. Theretaining window can be configured for coupling to an adapter housingone or more light guides for optically coupling said light guides to thelight module.

Further understanding of various aspects of the invention can beobtained by reference to the following detailed description inconjunction with the associated drawings, which are described brieflybelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a light module according to an embodimentof the present teachings,

FIG. 2A is a cross-sectional view of the light module depicted in FIG. 1illustrating various components thereof,

FIG. 2B is a schematic exploded view of the light module depicted inFIG. 1,

FIG. 3 schematically shows the light module of FIG. 1 and a light guideadapter that can be coupled to the light module,

FIG. 4 schematically depict an exemplary endoscope in which a lightmodule according to the present teachings in embedded,

FIG. 5 is a schematic cross-sectional view of lens suitable for use in alight module according to the present teachings,

FIG. 6 is a schematic cross-sectional view of a light module accordingto another embodiment,

FIG. 7 is a schematic perspective view of a lens employed in the lightmodule depicted in FIG. 6,

FIG. 8 is a top perspective view of a light module according to anotherembodiment,

FIG. 9 is another top perspective view of the light module depicted inFIG. 8,

FIG. 10 is a bottom perspective view of the light module depicted inFIG. 8,

FIG. 11 is a bottom view of the light module depicted in FIG. 8,

FIG. 12 is a perspective cross-sectional view of the light module,

FIG. 13 is a cross-sectional view of the light module,

FIG. 14 is a perspective exploded view of the light module,

FIG. 15 is a top perspective view of a window ring of the light module,

FIG. 16 is a bottom perspective view of the window ring,

FIG. 17 is a perspective view of an optical window of the light module,

FIG. 18 is a top perspective view of the lens of the light module,

FIG. 19 is another top perspective view of the lens of the light module,

FIG. 20 is a bottom perspective view of the lens of the light module,

FIG. 21 is a top view of the lens of the light module,

FIG. 22 is a bottom view of the lens of the light module,

FIG. 23 is side view of the lens of the light module,

FIG. 24 is a side sectional view of the lens of the light module,

FIG. 25 is a bottom lateral cross-sectional view of the lens of thelight module,

FIG. 26 is a top perspective view of a portion of the housing of thelight module configured for holding the lens,

FIG. 27 is a side cross-sectional view of the lens holder depicted inFIG. 26,

FIG. 28 is a top perspective view of an LED employed in a light moduleaccording to an embodiment, and

FIG. 29 is a bottom perspective view of the LED depicted in FIG. 28.

DETAILED DESCRIPTION

The present invention generally relates to a light module that can beincorporated in a variety of devices, such as medical and industrialendoscopes, to provide light for illuminating a field of view when thedevices are employed for their intended purpose. As discussed in moredetail below, in many embodiments, the light module can be removably andreplaceably embedded in a device, such as an endoscope, to efficientlytransfer light emitted by a light emitting diode (LED) to a light guide(e.g., an optical fiber or a bundle of optical fibers) of the device. Inparticular, in many embodiments, the light module employs a lens forcollecting light emitted by an LED over a large angular extent and toconverge that light for efficient coupling into a light guide.

Various terms are used herein consistent with their common meanings inthe art. By way of further explanation, a number of terms are definedbelow:

The term “optical power” is used herein consistent with its commonmeaning in the art to refer to the degree to which an optical componentor surface converges or diverges incident light and is equal to thereciprocal of the focal length of the component of the surface.

The term “numerical aperture” is used herein consistent with its commonmeaning in the art to refer to a dimensionless number that characterizesthe range of angles over which an optical component or system can emitor accept light.

The term “elliptical surface” or similar terms as used herein refer to asurface that is shaped as a section of an ellipse. In other words, anelliptical surface is in the form of a truncated ellipse.

The term “about” as used herein is intended to indicate a variation ofat most 10% around a numerical value.

The term “substantially” as used herein is intended to indicate adeviation of less than 5% relative to a complete state or condition.

With reference to FIGS. 1, 2A, 2B, and 3, a light module 100 accordingto an embodiment of the present teachings includes a substantiallycylindrical housing 102 that provides a hollow chamber 104 extendingfrom a proximal end (PE) to a distal end (DE). As discussed in moredetail below, the hollow chamber 104 can accommodate a plurality ofcomponents of the light module.

More specifically, the light module 100 includes a printed circuit board106 on which a light emitting diode (LED) 108 is mounted. The circuitboard 106 includes a pair of electrical leads 108 a/108 b for couplingthe circuit board to a source of electrical power for supplyingelectrical power to the LED 108 and in some cases controlling theintensity of the light emitted by the LED 108. In some embodiments, theLED 108 can have an emitting surface of approximately 1 mm×1 mm, and canbe coated with a wavelength conversion material (such as phosphorus) toemit a broadband continuum of visible light, e.g., at wavelengthsbetween about 470 and 700 nm. In some embodiments, the light emitted bythe LED 108 has a divergence angle (i.e., the angle within which about90% of the light is emitted) of about 160 degrees. In some embodiments,the LED 108 is a high-power LED (such as Luxeon III Model LXHL-LW3C),which can be operated at a typical forward voltage of 3.7 V and atypical operating current of 700 mA. In general, a variety of the LEDscan be employed, including, LEDs providing radiation at a variety ofdifferent wavelengths, such as 430 nm, 470 nm, near infrared, infrared,or visible. In some embodiments, multiple LEDs can be employed.

The light module 100 further includes a lens 112 having a lens body 112a providing an input surface 114 forming a cavity for at least partiallyreceiving the LED 108. At least a portion of the light emitted by LEDenters the lens body via the input surface 114. In some embodiments, theinput surface 114 receives at least about 80%, or at least about 90%, orat least about 95% (and preferably 100%) of the light emitted by the LED108. The lens 112 further includes an output surface 116 through whichlight can exit the lens body. As discussed further below, the lens 112further includes a collar 118 that partially encircles the lens body.The collar 118 includes a lower surface 118 a and an upper surface 118b.

In some embodiments, the light exits the lens with a numerical aperturein a range of about 0.5 to about 0.9, e.g., 0.66 or 0.88. In someembodiments, the lens is configured such that the numerical apertureassociated with the light exiting the lens allows efficient coupling ofthe light into a light guide that is optically coupled to the outputsurface of the lens to receive light therefrom. For example, in someembodiments, the numerical aperture associated with the light exitingthe lens can be substantially equal to an input numerical aperture of anoptical fiber (or a bundle of optical fibers) receiving light from thelens. A plurality of different types of light guides can be employed.For example, the light guide can be a single optical fiber, a bundle ofoptical fibers (e.g., a plurality of square or round-shaped opticalfibers), a liquid light guide, a plurality of tapers made from glass orplastic to form a light guide, etc.

A bottom plate 120 is coupled to the proximal end of the hollow shell104, which provides a seat for the circuit board 106. The bottom plate120 includes a pair of openings 120 a and 120 b through which theelectrical leads 108 a/108 b can protrude for coupling to a source ofelectrical power.

In this embodiment, the light module also includes a pair of sleeves122/124 disposed on opposite sides of the lens collar. In thisembodiment, each of the sleeves 122/124 is in the form of a cylindricalshell. More specifically, the sleeve 122 includes an annular shell 122 aextending between a bottom annular surface 122 b and a top annularsurface 122 c. When assembled within the hollow chamber 104, the bottomannular surface 122 b of the sleeve 122 is seated on an outer portion ofthe circuit board and the top annular surface 122 c is in contact withthe lower annular surface of the lens collar 118 to provide a seat forthe lens.

The sleeve 124 similarly includes an annular shell 124 a extendingbetween a bottom annular surface 124 b to a top annular surface 124 c.When assembled within the hollow chamber 104, the bottom annular surface124 b is in contact with the upper annular surface 118 b of the lenscollar. In this manner, the two sleeves 122 and 124 facilitatepositioning the lens within the hollow chamber 104 and providemechanical support for the lens.

In this embodiment, the light module includes an optical window 126 thatis optically coupled to the output surface 116 of the lens 112 such thatthe light exiting the lens (or at least a portion of that light) passesthrough the optical window 126 before exiting the light module. Morespecifically, when assembled within the hollow chamber 104, the opticalwindow 126 is seated on the top annular surface 124 c of the sleeve 12.In this embodiment, the optical window is in the form of a disk havinglower and upper flat faces 126 a and 126 b. In some embodiments, theoptical window can have a thickness in a range of about 0.5 mm to about2 mm, though other thicknesses can also be employed.

The optical window 126 can protect the output surface of the lens. Inaddition, in some embodiments, the optical window 126 can adjust one ormore characteristics of the light exiting the lens. By way of example,the optical window 126 can be selected to function as a filter, e.g., abandpass filter, to allow passage of certain wavelengths of the lightexiting the lens while blocking other wavelengths. For example, suchfiltering of the light exiting the lens can be used to adjust the colortemperature of the light. The optical window 126 can be formed of avariety of different materials, such as sapphire, quartz, glass, etc. Insome embodiments, the material from which the optical window 126 isformed is substantially transparent to visible radiation. In otherembodiments, the optical window 126 may be substantially transparent toradiation in another region of the electromagnetic spectrum. By way ofexample, in some embodiments in which the light module emits radiationin the infrared region of the electromagnetic spectrum, the opticalwindow 126 can be formed of high density polyethylene.

The light module 100 further includes a retaining window 128 (hereinalso referred to as a ring window) that can be removably and replaceablycoupled to the distal end of the housing 102. More specifically, withreference to FIGS. 2A and 2B, in this embodiment, the retaining window128 includes a plurality of external threads 128 a that can engage witha plurality of internal threads 102 a provided at the distal end of thehousing 102 a. The retaining window 128 has an annular shape providingan internal channel 129 extending from a lower opening 129 a to an upperopening 129 b for accommodating a light guide adapter, as discussed inmore detail below. The retaining window 128 includes a plurality ofinternal threads 128 b for engaging the retaining window with the lightguide adapter.

A gasket 127 is positioned between the retaining window 128 and theoptical window 126 such that when the components are assembled withinthe hollow chamber 104 the retaining window presses against the gasketto facilitate holding the optical window in place and providing a seal.

With reference to FIG. 3, the retaining window 128 can be removably andreplaceably coupled to an adapter 130, where the adapter can be in turncoupled to a light guide (e.g., an bundle of optical fibers) 132. Inthis embodiment, the adaptor 130 includes a plurality of externalthreads 130 a that can engage with the internal threads 128 b of theretaining window to removably and replaceably couple the adapter to theretaining window.

In this embodiment, the 130 adapter includes a substantially cylindricalhousing 130 b having an central hollow channel 130 c for receiving thelight guide 132. The housing includes an opening 130 d for receiving aretaining pin 130 e, which secures the light guide 132 within theadapter 130.

In some embodiments, an input surface(s) of the light guide 130 can bein contact with the upper surface 126 a of the optical window 126. Inother embodiments, the input surface(s) of the optical fiber can bepositioned at a small distance from the upper surface 126 a of theoptical window 126. In some embodiments, the input surface(s) of thelight guide is substantially flat and has an area substantially equal toan illuminated area of the upper surface of the optical window so as toallow efficient coupling of the light into the light guide. In someembodiments, a refractive index-matching material, such as a gel or anadhesive cement, can be applied to the upper surface 126 a of theoptical window 126 to facilitate efficient coupling of the light intothe light guide.

As noted above, a plurality of different types of light guides can beemployed. For example, the light guide 132 can be a single opticalfiber, a bundle of optical fibers (e.g., a plurality of square orround-shaped optical fibers), a liquid light guide, a plurality oftapers made from glass or plastic to form a light guide, etc.

In some embodiments, the light module transmits light emitted by the LED108 to a light guide coupled to the light module via the retainingwindow with an efficiency of at least about 30%, or at least about 40%,or at least about 50%, or at least about 60%, or at least about 70%, orat least about 80%, or at least about 90%, or at least about 95%. Inother words, the light module transfer at least about 30%, or at leastabout 40%, or at least about 50%, or at least about 60%, or at leastabout 70%, or at least about 80%, or at least about 90%, or at leastabout 95% of the light emitted by the LED to the light guide. In someembodiments, the numerical aperture associated with the light exitingthe light module to be coupled to a light guide is selected so as tooptimize efficient coupling of the light into the light guide. Forexample, the optical module can be configured for efficient coupling oflight into an optical fiber having an input numerical aperture of about0.5, 0.66, or 0.88. Further, optical fibers having a plurality of sizescan be employed to receive light from the light module. For example,fibers having a diameter of about 2.1 mm, about 3 mm, about 3.4 mm,about 4 mm, about 5 mm, or about 6 mm can be employed. For each fibersize, the lens can be configured, e.g., by adjusting the curvature ofits peripheral surface, the size of its output surface, to provideefficient coupling of the light emitted by the LED 108 into the opticalfiber, or a bundle of optical fibers.

Table 1 below presents theoretically simulated efficiency of variousimplementations of the light module 100 for coupling light into fibersof different sizes, where the lens size refers to the diameter of theoutput surface of the lens. The data presented in Table 1 shows thateven for a fiber size as small as 2.1 mm, the light module can couplelight emitted by an LED efficiently into the fiber. Further, the datashows that a lens size of 4 mm, efficient optical coupling of the lightinto different fiber sizes can be achieved.

TABLE 1 Fiber size (mm) 2.1 3.0 3.4 4.0 4.5 5.0 6.0 Lens 3.0 38.9 64.264.3 64.4 64.5 64.5 64.7 size 3.4 36.2 61.0 70.1 70.9 70.2 70.3 70.4(mm) 4.0 31.6 55.6 65.5 76.1 76.2 76.2 76.3 5.0 21.2 42.3 52.8 67.6 76.882.5 82.6 6.0 15.7 33.1 42.5 57.3 68.6 77.1 85.6

The light modules according to the present teachings provide a number ofadvantages. For example, such light modules can be embedded and easilyadapted for use with multiple types of different types of illuminationdevices. By way of example, the light modules according to the presentteachings may be embedded within medical or industrial endoscopes, videocameras, retractors, speculums, surgical headlights and other devicesrequiring high intensity, high quality light.

By way of example, FIG. 4 schematically depicts an endoscope 200according to an embodiment of the present teachings in which the lightmodule 100 is incorporated. More specifically, the endoscope 200includes a body 202 providing an enclosure 204 for removably andreplaceably receiving the light module 100. The endoscope 200 furtherincludes one or optical fibers 210 that are optically coupled to thelight module to receive light therefrom. The optical fibers extend to adistal end (DE) of the endoscope through which the light exits theendoscope to illuminate a field of view. The endoscope 200 can furtherinclude a light detector (not shown) and one or more optical components(not shown), such as lenses, mirrors, for directing light emanating froma field of view to the detector to form an image of the field of view,in a manner known in the art. Further, the exemplary endoscope 200 caninclude processing circuitry for forming the image and transmitting theimage via a proximal connector 210 to a monitor (not shown) for viewing,e.g., by a medical professional. The exemplary endoscope 200 can alsoinclude a user interface element 208 that allows a user to manipulatethe endoscope.

As noted above, in this embodiment, the lens 112 includes an inputsurface 114, and output surface 116 and an elliptical peripheral surface115 that is configured to reflect light incident thereon via totalinternal reflection. By way of further illustration, FIG. 5schematically depicts that the lens 112 includes a proximal section 113having the input surface 114 for receiving light from the LED 108 and adistal section 115 having the output surface 116 through which the lightexits the lens and a peripheral surface 116 a. In this embodiment, theperipheral surface 116 a of the distal section 115 of the lens is in theform of a truncated cone, though in other embodiments it can have adifferent shape. The collar 118 is positioned at the border between theproximal section and the distal section. In this embodiment, the inputsurface 114 of the lens 112 forms a cavity and includes a central convexportion 114 a surrounded by a peripheral portion 114 b. In thisembodiment, the peripheral portion 114 b of the input surface includes aproximal concave segment (A) and a distal convex segment (B). Theproximal section 113 includes an elliptical peripheral surface 117 thatis in the form of a truncated ellipse having two foci f1 (hereinreferred to as the input focus) and f2 (herein referred to as the outputfocus). The focus f1 is positioned in the input cavity on or inproximity of the LED and the other focus f2 is positioned external tothe lens at a distance (d), e.g., in a range of about 4 mm to about 6mm, above the output surface 116. In many embodiments, the output focusf2 is positioned so as to be within a proximal section of a light guideoptically coupled to the lens to ensure efficient coupling of the lightexiting the lens into the light guide.

In other embodiments, the output focus f2 can be within the lens body,e.g., below the lens' output surface or at the output surface. In someembodiments, the position of the distal focal point 1240 is selectedsuch that the light rays diverging from the distal focal point exhibitan angular spread across the input face of a light guide coupled to thelens that maximizes the coupling of the light into the light guide. Forexample, the diverging beam can have an angular spread commensurate withan input numerical aperture of the light guide.

In some embodiments, any of the convex portion 114 a and the ellipticalperipheral surface 117 exhibits a positive optical power in a range ofabout 50 Diopters to about 300 Diopters, though other optical powers canalso be employed. In some other embodiments, the convex portion isconfigured such that its focal point (i.e., the point at which the lightrays refracted by that portion converge) is external to the lens. By wayof example, the focal point of the convex portion may be within theproximal end of a light guide coupled to the lens, or external to boththe lens and the light pipe such that the light rays diverging form thefocal point to illuminate the input face of the light pipe would exhibita maximum angular spread corresponding to that of a solid anglesubtended by the input face of the light guide. By way of example, insome such embodiments, the focal point of the convex portion can besubstantially coincident with the distal focal point of the ellipticalperipheral surface.

The lens 112 can be formed of any suitable material, such as a varietyof different polymeric materials. Some examples of such materialsinclude, without limitation, polymethylmethacrylate (PMMA), andpolycarbonate. In some embodiments in which the LED 106 emits radiationin the infrared region of the electromagnetic spectrum, the lens may beformed of high density polyethylene to be substantially transparent tothat radiation wavelength. In some embodiments, the proximal and distalsections of the lens as well as the lens' collar are formed as a singleintegral unit, e.g., using molding or other manufacturing techniquesknown in the art.

With reference to FIG. 2A as well as FIG. 5, in some embodiments, thelens 112 is coupled to the LED 106 such that the distance between theLED and the convex portion 114 a of the input surface is less than about0.3 mm, or less than about 0.2 mm. In some cases, the distance betweenthe LED 106 and the convex portion 114 a of the input surface is about0.24 mm.

With reference to FIGS. 6 and 7, a light module 300 according to anotherembodiment includes a housing 301 in which a lens 302 can be removablyand replaceably positioned. The lens 302 includes an input surface 304that is optically coupled to an LED 306, which is mounted on a printedcircuit board 308, to receive light therefrom. The lens 302 furtherincludes an output surface 310 (which is substantially flat in thisembodiment) through which light exits the lens. The lens 302 alsoincludes a peripheral surface 312 that receives at least a portion ofthe light entering the lens through its input surface and directs thelight incident thereon via total internal reflection to the outputsurface. Similar to the previous embodiment, the peripheral surface 312is in the form of a truncated ellipse that includes an input focus f1 onor in close proximity of the LED 306 and an output focus f2 that isexternal to the lens at a distance, e.g., in a range of about 4 mm toabout 6 mm, above the lens' output surface 310. In some embodiments, theelliptical peripheral surface 312 can extend from the input surface ofthe lens to its output surface. In some other embodiments, a proximalportion 312 a of the peripheral surface of the lens can have anelliptical shape (e.g., a portion extending from the input surface to acollar 314), and a distal portion 312 b of the peripheral surface canhave a different shape (e.g., a truncated conical shape).

The collar (herein also referred to as flange) 314 partially encirclesthe lens body and facilitate the positioning of the lens within thehousing 301, as discussed in more detail below.

More specifically, a sleeve 316 in contact with a lower surface of thecollar 314 supports the lens 312 above the printed circuit board 308.Another sleeve 318 is seated on an upper surface of the lens collar 314and supports an optical window 320 at a distance D above the outputsurface 310 of the lens. The optical window 320 can be implemented, forexample, in a manner discussed above in connection with the previousembodiment.

A retaining window 322 is releasably coupled to the housing via aplurality of threads 322 a, which engage with respective threadsprovided in the inner surface of the housing 301. A gasket 322positioned between the retaining window 322 and the optical window 320can provide a seal. Similar to the previous embodiment, the retainingwindow 322 can be connected to an adapter 326 of a light guide (notshown) for optically coupling the light module 300 to the light guide.

The light module 300 includes a pair of electrical leads 300 a and 300 bfor connecting the light module to a source of electrical power, such asone or more batteries.

With reference to FIGS. 8-29, a light module 1 according to the anotherembodiment includes an external housing 5 having a lens holder 17 and awindow ring 8, which are releasably coupled to one another. In thisembodiment, the lens holder 17 contains a cylindrical internal channel19 with a top opening 20 and a bottom opening 21. The lens holder 17contains an internal shoulder 22 for holding an optical lens 3 withinthe internal channel 19. The lens holder 17 further includes a secondinternal shoulder 23 for holding a sapphire window 14 in substantiallyplanar arrangement over an output surface 4 of the optic lens 3. Thebottom opening 21 of the lens holder 17 permits any wiring or powersources to be operatively connected to the LEI) 2.

In this embodiment, the optical lens 3 is formed of a single piece oftransparent material that allows the passage of the light emitted by theLED 2 therethrough. For example, the lens 3 may be formed of glass,plastic, or sapphire. The lens 3 includes a proximal (orlight-receiving) section 9 having an input surface 10 for receivinglight from the LED 2, and a distal (or light-outputting) section 6having a substantially flat output surface 4. The optical lens 3 alsoincludes a collar 8 that can be seated on the internal shoulder 22 forbeing held within the lens holder 17. The input surface 10 includes aperipheral curved surface 12 and a central convex surface 13 thatcollectively form a cavity 11. The optical lens 3 includes a peripheralelliptical surface that reflects the light incident thereon via totalinternal reflection.

The window ring 18 includes a cylindrical internal channel 24 with a topopening 25 and a bottom opening 26. The window ring 18 contacts a topsurface 15 of the sapphire window 14 to secure the sapphire windowagainst the internal shoulder 23. In this embodiment, the bottom surfaceof the window ring 18 and the top surface of the lens holder 17 arethreaded for releasable attachment to one another.

The external housing 5 protects the LEI) 2, the elliptical optic lens 3,and the sapphire window 14 from the external environment. The resilientexternal housing 5 permits the module 1 to be attached to theillumination device without fear of misaligning or damaging the internalLED 2, the elliptical optic lens 3, and the sapphire window 14. In someembodiments, the lens holder 17 and the window ring 18 may be formed ofmetals, alloys, or plastics.

In some embodiments, the module 1 may be attached to a source of powerfor supplying electrical power to the LED 2 and any circuitry to providethe correct voltage to the LED 2, both of which are well known in theart. By way of example, the source of power can be one or morebatteries, or AC line power.

Similar to the previous embodiments, the light module 1 can be coupledto a light guide, e.g., the light guide of an illumination device, toprovide light from the LED 2 to the light guide. Once connected to apower source, the LED 2 emits light that spreads over an angular extent,e.g., an angular extent characterized by a divergence angle of about 160degrees. The light is received by the lens 3 via the cavity 11. In manyembodiments, a large fraction of the light emitted by the LED, and insome cases all the light emitted by the LED, is captured by the inputsurface 10 of the lens 3. The light entering the lens is transmitted viainternal reflection by its peripheral elliptical surface or directly toits output surface 4 and exits through that output surface. In someembodiments, the light exits the lens with a divergence angle less thanthe divergence angle associated with the light emitted by the LED. Forexample, the divergence angle associated with the light exiting the lenscan be about 30%, 40%, 50%, 60%, or 70% less than the divergence angleof the light emitted by the LED. For example, in some embodiments, thelight emitted by the LED 2 can be characterized by a divergence angle ofabout 160 degrees and the light exiting the lens can be characterized bya divergence angle of about 66 degrees. The light exiting the lenspasses through the sapphire window to be coupled to a light guide.

The substantially planar top surface 4 of the elliptical lens 3 isplaced in contact with the substantially planar bottom surface 16 of thesapphire window 14, or as close to this surface as mechanicallypossible. Ideally, both surfaces are as flat as possible, whichaccomplishes good contact or very minute separation across all or asubstantial portion of the interface between the planar surfaces. Theemitted light is transferred from the lens 3 to the sapphire window 14.

In some embodiments, the output surface 4 of the lens 3 can be indexmatched with the substantially planar bottom surface 16 of the sapphirewindow 14. For example, in some embodiments, refractive index-matchingmaterials, such as a liquid, a gel, or an adhesive cement, can beutilized to provide a refractive index match between the output surface4 of the lens 3 and the bottom surface 16 of the sapphire window.

Further, in some embodiments, the planar top surface 15 of the sapphirewindow 14 can be index matched with the input surface of the lightguide, e.g., input light guide of an illumination system. In someembodiments, the input light guide of the illumination device can have aflat input face, ideally filling the entire emitting area of planar topsurface 15 of the sapphire window 14. The input light guide face isplaced in contact with the planar top surface 15 of the sapphire window14 or as close to this surface as mechanically possible. Ideally, bothsurfaces are flat to facilitate good contact between them. Theflexibility of the input light guide may assist in a higher degree ofcontact between the two surfaces. This ensures efficient coupling oflight out of the planar top surface 15 of the sapphire window 14 intoinput light guide.

In embodiments of the subject invention, the planar top surface 15 ofthe sapphire window 14 may have an index-matching material such as aliquid, cement (adhesive), or gel, to substantially match the index ofrefraction of the input light guide to further improve the light coupledinto the light guide.

In some embodiments, the light guide can be a single light guide fiber,a plurality of square or round light guide fibers, liquid light guides,a plurality of plastic or glass fibers coupled to form a light guide, aplurality of plastic or glass rods coupled to form a light guide, aplurality of tapers made from glass or plastic fibers coupled to form alight guide, or a plurality of solid tapers made from glass or plasticcoupled to form a light guide.

The emitted light is transferred from the sapphire window 14 to thelight guide. As a result, a greater amount of light from the LED 2 canbe transmitted to the distal end of the light guide to illuminateobjects under investigation, e.g., in an endoscope system.

The lack of additional optics between the LED 2, the elliptical opticlens 3, and the sapphire window 14 simplifies the mechanical design andspace requirements for the module 1 allowing, for example, easierinsertion into existing illumination devices. In some embodiments, smallbatteries may be used to power the LED 2, thus permitting the lightmodule to be used in compact illumination device while providing adesired illumination

Those having ordinary skill in the art will appreciate that variouschanges can be made to the above embodiments without departing from thescope of the invention. Further, various elements of one embodiment canbe incorporate in another embodiment. For example, the lens of oneembodiment may be incorporate into another embodiment.

1.-44. (canceled)
 45. An adapter configured for removable and replaceable coupling to a light module, comprising: a housing having a plurality of external threads for engaging with a plurality of internal threads disposed at an end of the light module for coupling the adapter to the light module, said housing of the adapter having a central hollow channel for receiving at least a portion of a light guide.
 46. The adapter of claim 45, wherein said housing further comprises an opening on a lateral surface thereof.
 47. The adapter of claim 46, further comprising a retaining pin configured for being received in said opening for securing the light guide within the adapter.
 48. The adapter of claim 45, wherein said hollow channel is substantially cylindrical.
 49. The adapter of claim 45, wherein said light guide comprises an optical fiber.
 50. The adapter of claim 45, wherein said light guide comprises a bundle of optical fibers.
 51. The adapter of claim 45, wherein said light guide comprises a liquid light guide.
 52. The adapter of claim 45, wherein said light module comprises a retaining window.
 53. The adapter of claim 52, wherein said retaining window comprises a plurality of internal threads for engaging with said external threads of the housing of the adapter for coupling the adapter to the light guide.
 54. A light module, comprising: a housing providing a hollow chamber extending from a proximal end to a distal end, a lens positioned in the hollow chamber, the lens having a lens body comprising an input surface for receiving light from a light source and an output surface through which light exits the lens, an adapter configured for removable and replaceable coupling to the distal end of the hollow chamber of the housing, the adapter being further configured for receiving a proximal part of a light guide such that the light guide is secured within the adapter so as to receive at least a portion of the light exiting the output surface of the lens.
 55. The light module of claim 54, further wherein said adapter comprises an opening on a lateral surface thereof for receiving a retaining pin for securing the light guide within the adapter.
 56. The light module of claim 54, further comprising at least one sleeve disposed in said hollow chamber for facilitating positioning of the lens within said hollow chamber.
 57. The light module of claim 54, wherein said at least one sleeve comprises a pair of sleeves disposed on opposite sides of the lens. 